Farm prepares for future by earning carbon credits

Capturing and selling carbon credits is the wave of the future for Kevin Prevo's family farm near Bloomfield, Iowa. The Prevos have raised corn, beans, cattle, and hogs for five generations. Marketing carbon credits earned from the farm's regenerative practices will be one way the operation stays viable for the sixth generation, says Prevo.

At present, the Prevos — Kevin and his brothers, Jason and Kyle; their wives, Angela, Amanda, and Clarissa; along with their father and mother, Mark and Cindy — are treading lightly in the carbon market-place. However, their present efforts are positioning the farm for the future.

"I believe the steps we're taking are head-ed in the right direction," says Prevo. "It might be the sixth generation who'll really be able to take advantage of growth, both in the farm and in the carbon marketplace."

The Prevos partner with Indigo Ag to sell a small amount of carbon credits resulting from their new practice of eliminating the use of synthetic fertilizers across the farm. They also generate carbon credits by fine-tuning their application of hog manure to corn ground.
On their 1,400 acres of owned land, the Prevos custom feed up to 30,000 hogs a year. They also grow no-till corn, soybeans, and rye on 900 acres and manage 150 beef cow-calf pairs on 500 acres of pasture and hayfields, supplemented by fall and winter grazing on crop aftermath and cover crops.

"Because we've been no-tilling and raising cover crops for eight years, those practices didn't qualify for selling carbon credits," says Prevo. "We needed to have a new practice, and making changes in our fertilization practices was one way we could begin earning carbon credits. We received a small payment last year, and I expect we'll receive another one this year.

"We were going to make these changes anyway, so if we get a small payment from something we were already planning to do, it's a good deal," he adds.

"Besides that, we wanted to get in on this process of selling carbon credits early. That way, we'll have some experience in the marketplace for whenever we do take on new land and transition it to no-till and cover crops. I believe the payments will then be substantial, with new farming practices on newly acquired land."

The change the Prevos made in fertilization practices centers around fine-tuning manure application to eliminate synthetic fertilizer.

"We apply hog manure in fall to fields that will grow corn the following spring," says Prevo. "Using RTK [real-time kinetic] technology, we apply the manure in 30-inch strips. In spring, we plant directly on top of the manure strips. That eliminates the sidedressing of the liquid nitrogen we used to apply."

The Prevos plan to further adjust fertilizer use by applying manure at a variable rate instead of a fixed rate. They will apply more manure to highly productive ground and less manure to poorer ground.

"With the changes we've already made in fertilization practices, our corn yields might have dropped a little, but our bottom line is stronger because we're not buying fertilizer and we're getting better use out of the manure that we do apply," Prevo says.

System Keys Yields, Soil Health

While corn yields might have dropped as a result of the change in fertilization, the no-till/cover crop/grazing system as a whole has brought record soybean yields to the farm and increasing soil health.

"When we started no-tilling and raising cover crops, our goal was to eliminate erosion and increase water infiltration on our high-clay soils," says Prevo. "My father and grandfather always told us that here in Davis County we were always two weeks away from drought — even though it may have just rained. So, when we started with no-till and cover crops, we hoped we could stretch that critical period between rains to three weeks or even four weeks. We can definitely store more soil moisture now than we could eight years ago."

Key measurements on annual Haney soil tests show continual improvement as well. "The organic matter in our soil averages 0.2 to 0.3 of a percentage higher than it did seven years ago," says Prevo. "Along with that, soil tilth has improved dramatically."

Besides the no-till management of the soil, cover crops are key to improved soil health. While turnips and radishes sometimes augment the cover crop, cereal rye is the main cover crop the Prevos plant behind both corn and soybeans.

"We harvest corn the first of October, and we drill the rye in directly behind the combine," says Prevo. "We harvest soybeans the 10th or 15th of October, and we'll plant the rye right after that. We've planted rye clear into December, and we always get a good stand. Sometimes the fall growth will be 4 inches, and sometimes it'll be knee high. Regardless of fall growth, it always comes up in the spring."

The Prevos plant corn into the standing rye and terminate the cover crop two days later.

Soybeans in Cover Crop

Soybeans are a different story. " We plant beans into standing rye in late April or early May, but we won't terminate the rye until the end of May or the first of June," says Prevo. "We let the rye head out. The little soybeans just grow up in the rye. The rye might be waist high, and the beans will be a foot high inside the rye."

Letting the rye grow over the soybeans offers several advantages, Prevo believes. For starters, the hog manure applied in advance of the previous corn crop leaves "a lot of residual nitrogen in the soil," he points out. "The rye will take it up. The beans don't need it because they make their own nitrogen. But later, after we terminate the rye and it's dying, it releases the nitrogen back to the beans. The rye also keeps the ground cooler and helps to keep the microbes going. It also provides a lot of armor for the soil, which protects the soil from crusting in a hard rain." After harvest, the Prevos turn cattle into fields to graze crop aftermath and cover crops.

The moderate size of the Prevos' operation relative to the number of families it supports — along with off-farm income earned by Angela, Amanda, and Clarissa — speaks to the efficiency resulting from the whole-farm system.

"We believe we've created an efficient, sustainable process that can be passed on to the next generation," says Prevo. "Becoming involved in the carbon marketplace better positions the farm for the next generation. We can take increasing advantage of that opportunity in the future as the carbon marketplace grows."